Ubuntu 12.10 Looks To Use Intel SNA Acceleration
Phoronix: Ubuntu 12.10 Looks To Use Intel SNA Acceleration
Ubuntu developers are looking at enabling support for Intel SNA acceleration within the open-source graphics driver for the Ubuntu 12.10 release...
I know SNA stands for Sandy Bridge Architecture.
But could it be used with Radeon and Nouveau too?
Typo, just not -> not just
To cut a long story short: no, what is required most for the EXA drivers is an investment of engineering time to ensure that the drivers do not fallback (gradient shaders, trapezoid shders, handling over-sized destinations and sources, can mix core drawing operations with render, etc). To do so the EXA midlayer needs significant restructuring, in my opinion - I could not do the fallback prevention from within the UXA/EXA private interface and so tried with SNA to create a higher level private interface with the core code being a set of helpers for pixmap management and for exploiting alternative functional units within the hardware to avoid fallbacks when the 3D pipeline could not handle the render operation. (Though, from a purists point of view, there is still far too much midlayer in SNA.) The majority of the code is then written with initimate knowledge of both the Intel hardware and kernel driver, that code is itself not transferrable to other drivers, and given the limitations of the hardware it is likely that the other drivers would want to take a completely different approach for their GPUs. Once again, it is an issue of resources - there simply aren't enough developers working on the drivers and those that are are busy with OpenGL, which leads to interim solutions like glamor or st/xa where you try to write a common acceleration block which is then translated by the existing 3D drivers. Which still leaves you with the challenge of how to extend those interfaces to efficiently handle operations that are not directly implementable in the GL pipeline and for optimising those pipelines to handle the immediate mode rendering of X (which is a completely different kettle of fish than your typical game).
Originally Posted by uid313
SNA is not some magical invention of Intel, it's just bringing to the Intel driver the EXACT same way of doing 2D acceleration that radeon (at least r600 and newer, r300 still uses the dedicated 2D hardware) and noveau use.
Nope. UXA is the replica of doing 2D acceleration the same as radeon and nouveau, since it is just EXA with the pixmap migration taken out. I took a different approach, started from the shadow buffer and added cairo-drm, trying to build the foundations of a driver that played to the strengths of the hardware.
Originally Posted by Ansla
I was referring to the fact that SNA uses the 3D engine for the 2D acceleration instead of the dedicated 2D engine. From what I know this was the big difference between SNA and UXA. You say there are other features of it that would make sense for the rest of the drivers?